gpui: Add API for read and write active drag cursor style (#32028)

Prep for https://github.com/zed-industries/zed/pull/32040

Currently, there’s no way to modify the cursor style of the active drag
state after dragging begins. However, there are scenarios where we might
want to change the cursor style, such as pressing a modifier key while
dragging. This PR introduces an API to update and read the current
active drag state cursor.

Release Notes:

- N/A
10df7b5eb9Smit Barmase committed on 6/4/2025, 1:23:03 AM· committed by GitHubparent55120c4
1 file changedLine totals unavailable